/**
 * @author mrdoob / http://mrdoob.com/
 * @author supereggbert / http://www.paulbrunt.co.uk/
 * @author julianwa / https://github.com/julianwa
 */

THREE.RenderableObject = function () {

    this.id = 0;

    this.object = null;
    this.z = 0;

};

//

THREE.RenderableFace = function () {

    this.id = 0;

    this.v1 = new THREE.RenderableVertex();
    this.v2 = new THREE.RenderableVertex();
    this.v3 = new THREE.RenderableVertex();

    this.normalModel = new THREE.Vector3();

    this.vertexNormalsModel = [new THREE.Vector3(), new THREE.Vector3(), new THREE.Vector3()];
    this.vertexNormalsLength = 0;

    this.color = new THREE.Color();
    this.material = null;
    this.uvs = [new THREE.Vector2(), new THREE.Vector2(), new THREE.Vector2()];

    this.z = 0;

};

//

THREE.RenderableVertex = function () {

    this.position = new THREE.Vector3();
    this.positionWorld = new THREE.Vector3();
    this.positionScreen = new THREE.Vector4();

    this.visible = true;

};

THREE.RenderableVertex.prototype.copy = function (vertex) {

    this.positionWorld.copy(vertex.positionWorld);
    this.positionScreen.copy(vertex.positionScreen);

};

//

THREE.RenderableLine = function () {

    this.id = 0;

    this.v1 = new THREE.RenderableVertex();
    this.v2 = new THREE.RenderableVertex();

    this.vertexColors = [new THREE.Color(), new THREE.Color()];
    this.material = null;

    this.z = 0;

};

//

THREE.RenderableSprite = function () {

    this.id = 0;

    this.object = null;

    this.x = 0;
    this.y = 0;
    this.z = 0;

    this.rotation = 0;
    this.scale = new THREE.Vector2();

    this.material = null;

};

//

THREE.Projector = function () {

    var _object, _objectCount, _objectPool = [], _objectPoolLength = 0,
        _vertex, _vertexCount, _vertexPool = [], _vertexPoolLength = 0,
        _face, _faceCount, _facePool = [], _facePoolLength = 0,
        _line, _lineCount, _linePool = [], _linePoolLength = 0,
        _sprite, _spriteCount, _spritePool = [], _spritePoolLength = 0,

        _renderData = {objects: [], lights: [], elements: []},

        _vector3 = new THREE.Vector3(),
        _vector4 = new THREE.Vector4(),

        _clipBox = new THREE.Box3(new THREE.Vector3(-1, -1, -1), new THREE.Vector3(1, 1, 1)),
        _boundingBox = new THREE.Box3(),
        _points3 = new Array(3),
        _points4 = new Array(4),

        _viewMatrix = new THREE.Matrix4(),
        _viewProjectionMatrix = new THREE.Matrix4(),

        _modelMatrix,
        _modelViewProjectionMatrix = new THREE.Matrix4(),

        _normalMatrix = new THREE.Matrix3(),

        _frustum = new THREE.Frustum(),

        _clippedVertex1PositionScreen = new THREE.Vector4(),
        _clippedVertex2PositionScreen = new THREE.Vector4();

    //

    this.projectVector = function (vector, camera) {

        console.warn('THREE.Projector: .projectVector() is now vector.project().');
        vector.project(camera);

    };

    this.unprojectVector = function (vector, camera) {

        console.warn('THREE.Projector: .unprojectVector() is now vector.unproject().');
        vector.unproject(camera);

    };

    this.pickingRay = function (vector, camera) {

        console.error('THREE.Projector: .pickingRay() is now raycaster.setFromCamera().');

    };

    //

    var RenderList = function () {

        var normals = [];
        var uvs = [];

        var object = null;
        var material = null;

        var normalMatrix = new THREE.Matrix3();

        var setObject = function (value) {

            object = value;
            material = object.material;

            normalMatrix.getNormalMatrix(object.matrixWorld);

            normals.length = 0;
            uvs.length = 0;

        };

        var projectVertex = function (vertex) {

            var position = vertex.position;
            var positionWorld = vertex.positionWorld;
            var positionScreen = vertex.positionScreen;

            positionWorld.copy(position).applyMatrix4(_modelMatrix);
            positionScreen.copy(positionWorld).applyMatrix4(_viewProjectionMatrix);

            var invW = 1 / positionScreen.w;

            positionScreen.x *= invW;
            positionScreen.y *= invW;
            positionScreen.z *= invW;

            vertex.visible = positionScreen.x >= -1 && positionScreen.x <= 1 &&
                positionScreen.y >= -1 && positionScreen.y <= 1 &&
                positionScreen.z >= -1 && positionScreen.z <= 1;

        };

        var pushVertex = function (x, y, z) {

            _vertex = getNextVertexInPool();
            _vertex.position.set(x, y, z);

            projectVertex(_vertex);

        };

        var pushNormal = function (x, y, z) {

            normals.push(x, y, z);

        };

        var pushUv = function (x, y) {

            uvs.push(x, y);

        };

        var checkTriangleVisibility = function (v1, v2, v3) {

            if (v1.visible === true || v2.visible === true || v3.visible === true) return true;

            _points3[0] = v1.positionScreen;
            _points3[1] = v2.positionScreen;
            _points3[2] = v3.positionScreen;

            return _clipBox.isIntersectionBox(_boundingBox.setFromPoints(_points3));

        };

        var checkBackfaceCulling = function (v1, v2, v3) {

            return ((v3.positionScreen.x - v1.positionScreen.x) *
                (v2.positionScreen.y - v1.positionScreen.y) -
                (v3.positionScreen.y - v1.positionScreen.y) *
                (v2.positionScreen.x - v1.positionScreen.x)) < 0;

        };

        var pushLine = function (a, b) {

            var v1 = _vertexPool[a];
            var v2 = _vertexPool[b];

            _line = getNextLineInPool();

            _line.id = object.id;
            _line.v1.copy(v1);
            _line.v2.copy(v2);
            _line.z = (v1.positionScreen.z + v2.positionScreen.z) / 2;

            _line.material = object.material;

            _renderData.elements.push(_line);

        };

        var pushTriangle = function (a, b, c) {

            var v1 = _vertexPool[a];
            var v2 = _vertexPool[b];
            var v3 = _vertexPool[c];

            if (checkTriangleVisibility(v1, v2, v3) === false) return;

            if (material.side === THREE.DoubleSide || checkBackfaceCulling(v1, v2, v3) === true) {

                _face = getNextFaceInPool();

                _face.id = object.id;
                _face.v1.copy(v1);
                _face.v2.copy(v2);
                _face.v3.copy(v3);
                _face.z = (v1.positionScreen.z + v2.positionScreen.z + v3.positionScreen.z) / 3;

                for (var i = 0; i < 3; i++) {

                    var offset = arguments[i] * 3;
                    var normal = _face.vertexNormalsModel[i];

                    normal.set(normals[offset], normals[offset + 1], normals[offset + 2]);
                    normal.applyMatrix3(normalMatrix).normalize();

                    var offset2 = arguments[i] * 2;

                    var uv = _face.uvs[i];
                    uv.set(uvs[offset2], uvs[offset2 + 1]);

                }

                _face.vertexNormalsLength = 3;

                _face.material = object.material;

                _renderData.elements.push(_face);

            }

        };

        return {
            setObject: setObject,
            projectVertex: projectVertex,
            checkTriangleVisibility: checkTriangleVisibility,
            checkBackfaceCulling: checkBackfaceCulling,
            pushVertex: pushVertex,
            pushNormal: pushNormal,
            pushUv: pushUv,
            pushLine: pushLine,
            pushTriangle: pushTriangle
        }

    };

    var renderList = new RenderList();

    this.projectScene = function (scene, camera, sortObjects, sortElements) {

        _faceCount = 0;
        _lineCount = 0;
        _spriteCount = 0;

        _renderData.elements.length = 0;

        if (scene.autoUpdate === true) scene.updateMatrixWorld();
        if (camera.parent === undefined) camera.updateMatrixWorld();

        _viewMatrix.copy(camera.matrixWorldInverse.getInverse(camera.matrixWorld));
        _viewProjectionMatrix.multiplyMatrices(camera.projectionMatrix, _viewMatrix);

        _frustum.setFromMatrix(_viewProjectionMatrix);

        //

        _objectCount = 0;

        _renderData.objects.length = 0;
        _renderData.lights.length = 0;

        scene.traverseVisible(function (object) {

            if (object instanceof THREE.Light) {

                _renderData.lights.push(object);

            } else if (object instanceof THREE.Mesh || object instanceof THREE.Line || object instanceof THREE.Sprite) {

                if (object.material.visible === false) return;

                if (object.frustumCulled === false || _frustum.intersectsObject(object) === true) {

                    _object = getNextObjectInPool();
                    _object.id = object.id;
                    _object.object = object;

                    _vector3.setFromMatrixPosition(object.matrixWorld);
                    _vector3.applyProjection(_viewProjectionMatrix);
                    _object.z = _vector3.z;

                    _renderData.objects.push(_object);

                }

            }

        });

        if (sortObjects === true) {

            _renderData.objects.sort(painterSort);

        }

        //

        for (var o = 0, ol = _renderData.objects.length; o < ol; o++) {

            var object = _renderData.objects[o].object;
            var geometry = object.geometry;

            renderList.setObject(object);

            _modelMatrix = object.matrixWorld;

            _vertexCount = 0;

            if (object instanceof THREE.Mesh) {

                if (geometry instanceof THREE.BufferGeometry) {

                    var attributes = geometry.attributes;
                    var offsets = geometry.offsets;

                    if (attributes.position === undefined) continue;

                    var positions = attributes.position.array;

                    for (var i = 0, l = positions.length; i < l; i += 3) {

                        renderList.pushVertex(positions[i], positions[i + 1], positions[i + 2]);

                    }

                    if (attributes.normal !== undefined) {

                        var normals = attributes.normal.array;

                        for (var i = 0, l = normals.length; i < l; i += 3) {

                            renderList.pushNormal(normals[i], normals[i + 1], normals[i + 2]);

                        }

                    }

                    if (attributes.uv !== undefined) {

                        var uvs = attributes.uv.array;

                        for (var i = 0, l = uvs.length; i < l; i += 2) {

                            renderList.pushUv(uvs[i], uvs[i + 1]);

                        }

                    }

                    if (attributes.index !== undefined) {

                        var indices = attributes.index.array;

                        if (offsets.length > 0) {

                            for (var o = 0; o < offsets.length; o++) {

                                var offset = offsets[o];
                                var index = offset.index;

                                for (var i = offset.start, l = offset.start + offset.count; i < l; i += 3) {

                                    renderList.pushTriangle(indices[i] + index, indices[i + 1] + index, indices[i + 2] + index);

                                }

                            }

                        } else {

                            for (var i = 0, l = indices.length; i < l; i += 3) {

                                renderList.pushTriangle(indices[i], indices[i + 1], indices[i + 2]);

                            }

                        }

                    } else {

                        for (var i = 0, l = positions.length / 3; i < l; i += 3) {

                            renderList.pushTriangle(i, i + 1, i + 2);

                        }

                    }

                } else if (geometry instanceof THREE.Geometry) {

                    var vertices = geometry.vertices;
                    var faces = geometry.faces;
                    var faceVertexUvs = geometry.faceVertexUvs[0];

                    _normalMatrix.getNormalMatrix(_modelMatrix);

                    var material = object.material;

                    var isFaceMaterial = material instanceof THREE.MeshFaceMaterial;
                    var objectMaterials = isFaceMaterial === true ? object.material : null;

                    for (var v = 0, vl = vertices.length; v < vl; v++) {

                        var vertex = vertices[v];

                        _vector3.copy(vertex);

                        if (material.morphTargets === true) {

                            var morphTargets = geometry.morphTargets;
                            var morphInfluences = object.morphTargetInfluences;

                            for (var t = 0, tl = morphTargets.length; t < tl; t++) {

                                var influence = morphInfluences[t];

                                if (influence === 0) continue;

                                var target = morphTargets[t];
                                var targetVertex = target.vertices[v];

                                _vector3.x += (targetVertex.x - vertex.x) * influence;
                                _vector3.y += (targetVertex.y - vertex.y) * influence;
                                _vector3.z += (targetVertex.z - vertex.z) * influence;

                            }

                        }

                        renderList.pushVertex(_vector3.x, _vector3.y, _vector3.z);

                    }

                    for (var f = 0, fl = faces.length; f < fl; f++) {

                        var face = faces[f];

                        var material = isFaceMaterial === true
                            ? objectMaterials.materials[face.materialIndex]
                            : object.material;

                        if (material === undefined) continue;

                        var side = material.side;

                        var v1 = _vertexPool[face.a];
                        var v2 = _vertexPool[face.b];
                        var v3 = _vertexPool[face.c];

                        if (renderList.checkTriangleVisibility(v1, v2, v3) === false) continue;

                        var visible = renderList.checkBackfaceCulling(v1, v2, v3);

                        if (side !== THREE.DoubleSide) {
                            if (side === THREE.FrontSide && visible === false) continue;
                            if (side === THREE.BackSide && visible === true) continue;
                        }

                        _face = getNextFaceInPool();

                        _face.id = object.id;
                        _face.v1.copy(v1);
                        _face.v2.copy(v2);
                        _face.v3.copy(v3);

                        _face.normalModel.copy(face.normal);

                        if (visible === false && (side === THREE.BackSide || side === THREE.DoubleSide)) {

                            _face.normalModel.negate();

                        }

                        _face.normalModel.applyMatrix3(_normalMatrix).normalize();

                        var faceVertexNormals = face.vertexNormals;

                        for (var n = 0, nl = Math.min(faceVertexNormals.length, 3); n < nl; n++) {

                            var normalModel = _face.vertexNormalsModel[n];
                            normalModel.copy(faceVertexNormals[n]);

                            if (visible === false && (side === THREE.BackSide || side === THREE.DoubleSide)) {

                                normalModel.negate();

                            }

                            normalModel.applyMatrix3(_normalMatrix).normalize();

                        }

                        _face.vertexNormalsLength = faceVertexNormals.length;

                        var vertexUvs = faceVertexUvs[f];

                        if (vertexUvs !== undefined) {

                            for (var u = 0; u < 3; u++) {

                                _face.uvs[u].copy(vertexUvs[u]);

                            }

                        }

                        _face.color = face.color;
                        _face.material = material;

                        _face.z = (v1.positionScreen.z + v2.positionScreen.z + v3.positionScreen.z) / 3;

                        _renderData.elements.push(_face);

                    }

                }

            } else if (object instanceof THREE.Line) {

                if (geometry instanceof THREE.BufferGeometry) {

                    var attributes = geometry.attributes;

                    if (attributes.position !== undefined) {

                        var positions = attributes.position.array;

                        for (var i = 0, l = positions.length; i < l; i += 3) {

                            renderList.pushVertex(positions[i], positions[i + 1], positions[i + 2]);

                        }

                        if (attributes.index !== undefined) {

                            var indices = attributes.index.array;

                            for (var i = 0, l = indices.length; i < l; i += 2) {

                                renderList.pushLine(indices[i], indices[i + 1]);

                            }

                        } else {

                            var step = object.mode === THREE.LinePieces ? 2 : 1;

                            for (var i = 0, l = (positions.length / 3) - 1; i < l; i += step) {

                                renderList.pushLine(i, i + 1);

                            }

                        }

                    }

                } else if (geometry instanceof THREE.Geometry) {

                    _modelViewProjectionMatrix.multiplyMatrices(_viewProjectionMatrix, _modelMatrix);

                    var vertices = object.geometry.vertices;

                    if (vertices.length === 0) continue;

                    v1 = getNextVertexInPool();
                    v1.positionScreen.copy(vertices[0]).applyMatrix4(_modelViewProjectionMatrix);

                    // Handle LineStrip and LinePieces
                    var step = object.mode === THREE.LinePieces ? 2 : 1;

                    for (var v = 1, vl = vertices.length; v < vl; v++) {

                        v1 = getNextVertexInPool();
                        v1.positionScreen.copy(vertices[v]).applyMatrix4(_modelViewProjectionMatrix);

                        if ((v + 1) % step > 0) continue;

                        v2 = _vertexPool[_vertexCount - 2];

                        _clippedVertex1PositionScreen.copy(v1.positionScreen);
                        _clippedVertex2PositionScreen.copy(v2.positionScreen);

                        if (clipLine(_clippedVertex1PositionScreen, _clippedVertex2PositionScreen) === true) {

                            // Perform the perspective divide
                            _clippedVertex1PositionScreen.multiplyScalar(1 / _clippedVertex1PositionScreen.w);
                            _clippedVertex2PositionScreen.multiplyScalar(1 / _clippedVertex2PositionScreen.w);

                            _line = getNextLineInPool();

                            _line.id = object.id;
                            _line.v1.positionScreen.copy(_clippedVertex1PositionScreen);
                            _line.v2.positionScreen.copy(_clippedVertex2PositionScreen);

                            _line.z = Math.max(_clippedVertex1PositionScreen.z, _clippedVertex2PositionScreen.z);

                            _line.material = object.material;

                            if (object.material.vertexColors === THREE.VertexColors) {

                                _line.vertexColors[0].copy(object.geometry.colors[v]);
                                _line.vertexColors[1].copy(object.geometry.colors[v - 1]);

                            }

                            _renderData.elements.push(_line);

                        }

                    }

                }

            } else if (object instanceof THREE.Sprite) {

                _vector4.set(_modelMatrix.elements[12], _modelMatrix.elements[13], _modelMatrix.elements[14], 1);
                _vector4.applyMatrix4(_viewProjectionMatrix);

                var invW = 1 / _vector4.w;

                _vector4.z *= invW;

                if (_vector4.z >= -1 && _vector4.z <= 1) {

                    _sprite = getNextSpriteInPool();
                    _sprite.id = object.id;
                    _sprite.x = _vector4.x * invW;
                    _sprite.y = _vector4.y * invW;
                    _sprite.z = _vector4.z;
                    _sprite.object = object;

                    _sprite.rotation = object.rotation;

                    _sprite.scale.x = object.scale.x * Math.abs(_sprite.x - (_vector4.x + camera.projectionMatrix.elements[0]) / (_vector4.w + camera.projectionMatrix.elements[12]));
                    _sprite.scale.y = object.scale.y * Math.abs(_sprite.y - (_vector4.y + camera.projectionMatrix.elements[5]) / (_vector4.w + camera.projectionMatrix.elements[13]));

                    _sprite.material = object.material;

                    _renderData.elements.push(_sprite);

                }

            }

        }

        if (sortElements === true) {

            _renderData.elements.sort(painterSort);

        }

        return _renderData;

    };

    // Pools

    function getNextObjectInPool() {

        if (_objectCount === _objectPoolLength) {

            var object = new THREE.RenderableObject();
            _objectPool.push(object);
            _objectPoolLength++;
            _objectCount++;
            return object;

        }

        return _objectPool[_objectCount++];

    }

    function getNextVertexInPool() {

        if (_vertexCount === _vertexPoolLength) {

            var vertex = new THREE.RenderableVertex();
            _vertexPool.push(vertex);
            _vertexPoolLength++;
            _vertexCount++;
            return vertex;

        }

        return _vertexPool[_vertexCount++];

    }

    function getNextFaceInPool() {

        if (_faceCount === _facePoolLength) {

            var face = new THREE.RenderableFace();
            _facePool.push(face);
            _facePoolLength++;
            _faceCount++;
            return face;

        }

        return _facePool[_faceCount++];


    }

    function getNextLineInPool() {

        if (_lineCount === _linePoolLength) {

            var line = new THREE.RenderableLine();
            _linePool.push(line);
            _linePoolLength++;
            _lineCount++
            return line;

        }

        return _linePool[_lineCount++];

    }

    function getNextSpriteInPool() {

        if (_spriteCount === _spritePoolLength) {

            var sprite = new THREE.RenderableSprite();
            _spritePool.push(sprite);
            _spritePoolLength++;
            _spriteCount++
            return sprite;

        }

        return _spritePool[_spriteCount++];

    }

    //

    function painterSort(a, b) {

        if (a.z !== b.z) {

            return b.z - a.z;

        } else if (a.id !== b.id) {

            return a.id - b.id;

        } else {

            return 0;

        }

    }

    function clipLine(s1, s2) {

        var alpha1 = 0, alpha2 = 1,

            // Calculate the boundary coordinate of each vertex for the near and far clip planes,
            // Z = -1 and Z = +1, respectively.
            bc1near = s1.z + s1.w,
            bc2near = s2.z + s2.w,
            bc1far = -s1.z + s1.w,
            bc2far = -s2.z + s2.w;

        if (bc1near >= 0 && bc2near >= 0 && bc1far >= 0 && bc2far >= 0) {

            // Both vertices lie entirely within all clip planes.
            return true;

        } else if ((bc1near < 0 && bc2near < 0) || (bc1far < 0 && bc2far < 0)) {

            // Both vertices lie entirely outside one of the clip planes.
            return false;

        } else {

            // The line segment spans at least one clip plane.

            if (bc1near < 0) {

                // v1 lies outside the near plane, v2 inside
                alpha1 = Math.max(alpha1, bc1near / (bc1near - bc2near));

            } else if (bc2near < 0) {

                // v2 lies outside the near plane, v1 inside
                alpha2 = Math.min(alpha2, bc1near / (bc1near - bc2near));

            }

            if (bc1far < 0) {

                // v1 lies outside the far plane, v2 inside
                alpha1 = Math.max(alpha1, bc1far / (bc1far - bc2far));

            } else if (bc2far < 0) {

                // v2 lies outside the far plane, v2 inside
                alpha2 = Math.min(alpha2, bc1far / (bc1far - bc2far));

            }

            if (alpha2 < alpha1) {

                // The line segment spans two boundaries, but is outside both of them.
                // (This can't happen when we're only clipping against just near/far but good
                //  to leave the check here for future usage if other clip planes are added.)
                return false;

            } else {

                // Update the s1 and s2 vertices to match the clipped line segment.
                s1.lerp(s2, alpha1);
                s2.lerp(s1, 1 - alpha2);

                return true;

            }

        }

    }

};
